Propeller shaft



rmaa a, 14, 1935 A Y 2,001,1 7

UNITED STATES PATENT OFFICE Benjamin A. Sm more, 111., mm, a

meme assignments, to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Application November 21, 193:, Serial No. 099,856

8 Claims. (01. 04-29) This invention relates to propeller shafts for monic resonance. This resonance may be the remotor vehicles. sult of the direct forces, above mentioned, or due In the construction of motor vehicles considto sympathetic harmonic resonance. That is to erable attention has been given to the matter say, the deflections of an ordinary tubular pro- 6 of absorbing vibration and deadening sound. peller shaft incident to operationof the motor Practically every part of the car has been studied vehicle are found to cause a distinct noise atwith that object inview but, so far as I am aware. tributable to the resonance ofithe part. Then, there has been no improvement made in the protoo, sympathetic vibration of an ordinary tubupeller shaft to overcome the objectionable noise lar propeller shaft causes a distinct noise to be 1 due to the resonance of this tubular part which heard at certain critical speeds where such vibra- 10 asserts itself at certain critical speeds, nor any" tion manifests itself. Thevlbrations which the improvement with a view to diminishing if not propeller shaft may fall in with in the way of entirely eliminating its susceptibility to trans sympathetic vibrations, may be created or occur mitting vibrations, created or occurring in either either in the rear axle or in any part of the of the mechanisms ahead and behind the promechanism in front of the propeller shaft, and; 5

p'eller shaft. It is, therefore, the principal obof course, some vibrations occurring ahead or ject of my invention to provide a non-resonant behind the propeller shaft may be. transmitted and vibration dampening propeller shaft. directly through the propeller shaft unless the The propeller shaft of my invention is tubular same is properly constructed to dampen out such and sheathed inside or outside, or both inside vibration. An ordinary propeller shaft being of 20 and outside with material having a different tubular section also has a harmonic vibration by period of vibration to dampen the vibration of reason of the closed air space. the shaft and avoid the phenomena of resonance. Inaccordance with my invention, the shaft Ill This application is a continuation in partof O is sheathed internally and externally as indi-' my copending application, Serial No.' 615,917, cated at I and 26, respectively, in Fig. 2. The 25 filed June 7,1932. sheathing may be of rubber or any other mate- The invention is disclosed in the accompanyrial suitable for the purpose either to dampen ing drawing, in whichout the vibrations of the tubular shaft or to set Figure 1 shows apropeller shaft and its uniup vibrations out of phase with the vibrations of so versal ioint'connection's, the shaft being sheathed the tubular shaft and thus provide a nonin accordance with my invention asindicated in resonant propeller shaft, one which will operate cross-section, Fig. 2, and without the objectionable noise experienced with Fig. 3 is another cross-section similar to Fig. 2 other unimproved tubular propeller shafts. The but showing a modification in which sound deadsheathing, although shown inside and outside, ening material is used as a coating on the inside may be provided on the inside alone or on the of the shaft. outside alone. In any event, it is apparent that Similar reference numerals are applied to corvery little weight is added to the shaft andthe responding parts throughout the views. I sheathing is truly concentric with the shaft and Referring first to Figure l, the propeller shaft cannot, therefore, disturb dynamic balance. The is indicated by the reference numeral [0. It is sheathing may rely simply upon frictional con- 40 tubular like other propeller shafts and joined tact with the .walls of the shaft to accomplish at its rear end to the yoke I I of a universal joint the result intended, or may be suitably cemented I! to transmit power to the driven spindle in the in place.

rear axle housing of the motor vehicle on which In Fig. 3 I have shown a coating 21 of finely 4 the propeller shaft ismounted. The front end divided felt sprayed on the inside of the tubular of the shaft carries a splined part l3 received shaft lfl, using a suitable liquid cement in the within the slip yoke I l of the" front universal spraying to cause the felt to adhere. This costioint: ll so as to make connection with the gear ing' of felt is provided of the proper thickness to set. The connections at the front and rear give the sound deadening effect desired and thus may be completed through the conventional eliminate the phenomena of resonance. 50 coupling flanges I6 and II, or in any other suit- It is believed the foregoing description conable or preferred manner. veys a good understanding of all of the objects The propeller shaft I0 is subjected to torsional, and advantages of my invention. The appended column or strut, and beam deflections. Being of claims have been drawn to cover all legitimate regular section it is also subject to natural harmodifications and adaptations.

I claim: 1. In a motor vehicle power tron train,

a hollow propeller shaft having suitable power transmitting connections at opposite ends, and means of tubular form, so as to tit said shaft. engaging the walls thereof and having periodical vibrations during rotation out of phase with the vibrations of said walls whereby to buck the same and render the shaft substantially non-resonant.

2. In a motor vehicle power ton train, a hollow propeller shaft having suitable power transmitting connections at opposite ends.

4. A propeller shaft for motor vehicles. comprising a rotary tubular member having an internal tubular sheathingof non-metallic material rotatable therewith for the purpose stated.

5. A propeller shaft for motor vehicles comprising a rotary tubular member having an external tubular sheathing of non-metallic material rotatable therewith for the purpose stated.

6. A propeller shaft for motor vehicles comprising a rotary tubular member having and external tubular sheathings of non-metallic material rotatable therewith for the purpose stated.

7. A propeller shaft for motor vehicles cominternal "1o prising a tubular metallic member coated on the 5 inside witha tubular layer of sound deadening material to render the member substantially non-resonant. v

I. A propeller shaft for motor vehicles coma tubular metallic member having its'zo walls coated with a tubular lwer of sound deadeningmaterial to render the member substantially non-res'onan v BENJAMIN A. SWENNEB. 

